Aslong as the track didnt break its all good, you can do it yourself.
Get someone to operate the radio (on and off) for you as it'll hopefully work this time round.
Turn the radio on, after you cant hear the motor noise anymore, slide the track into the little hole as far as you can without any force, then get the other person to turn the radio off, this should trigger it to wind the track in, aslong as you have the track facing the right way so it grabs into the teeth, it should pull the track down if you gently guide it in.